download_attachment

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description says it downloads into QQBOT_MCP_DOWNLOAD_DIR and returns a local path, which means it creates a local file. That contradicts the readOnlyHint=true annotation, which claims the tool does not modify its environment. The SSRF guard and size cap disclosures are useful, but the annotation contradiction is decisive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense sentences with no filler. The core action, destination, safeguards, and return value are all front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, and the description usefully states that a local path is returned. However, with 0% schema description coverage, it omits filename handling, max_bytes details, overwrite behavior, and failure modes, so it is only minimally complete for a 3-parameter tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate and only partially does. It clarifies that the URL is an attachment URL and implies max_bytes via 'size cap', but never mentions the filename parameter or explains defaults, limits, or behavior when the size cap is exceeded.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: download an attachment URL, with examples of message images/files and media URLs. The destination directory and returned local path make the scope clear, and no siblings overlap with this attachment-downloading behavior.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description makes clear that this is for downloading message image/file/media URLs, which is enough context to select it over the API/event siblings. It does not explicitly state when not to use it or name alternatives, but no alternative download tool exists among the siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.